Problem: Solve for $n$ : $18 = 16 + n$
Solution: Subtract $16$ from both sides: $ \begin{eqnarray} \\ \hphantom{18 {- 16}} &\hphantom{=}& \hphantom{n} \\ 18 &=& 16 + n \\ \\ {-16} && {-16} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ 18 {- 16} &=& n \\ \end{eqnarray} $ Simplify. $ n = 2$